qvPDF is a PDF creator for Windows. It's implemented as printer driver and uses plugins to execute different actions after creating the PDF. Processing parameters can be written directly into the printed document like: @|mapi.mailto=me@you.de|@

Application written in C# to store references for papers, convert them to APA format and then retrieve them again later (if needed). Not a ground-breaking application by any means, but it does the job.